Determination of nucleotide sequences transcribed from rabbit hemoglobin cDNA -- The sequences of virtually all of the fragments resulting from cleavage at G residues have been completed. From correspondence with the amino acid sequences it has been possible to estimate that about 500 nucleotides of the structural gene are trans-cribed and to assign sequences for about 222 nucleotides. It has further been possible to assign fragments totalling about 97 nucleotides to the untranslated regions of the mRNAs because they have no possible fit with the structural gene, and to show that most or probably all of these are from the untranslated region of the beta mRNA. Apparently the in vitro transcription terminates near the end of the structural gene in the alpha mRNA. Further work will be directed toward the completion of the entire sequence of these regions.